Continuity mistake: When Alex goes home in the night, he turns on his cassette player, takes out a cassette from the player, then after a few seconds a closeup is shown of the slot with a cassette inside that he removes again. (00:18:25)
Continuity mistake: When Frank first pours the wine for Alex he fills it all the way to the top. The shot changes and he is still pouring the wine however the level of the glass has dropped to half full and he fills it up again.
Continuity mistake: When Alex is informed that he's being transferred to the Ludovico center, the governor's arms jump from his lap to under his chin, then back to his lap. (01:06:00)
Chosen answer: Since this is a futuristic police state, it's likely that Mr. Alexander was dealt with the way dissenters are often dealt with in such situations (Execution or lifelong imprisonment.). In the book, he wrote literature protesting the police state. (The phrase "A Clockwork Orange" comes from a pamphlet he wrote.) Alex and his droogs kicked and beat him while they raped his wife. A while later, the doctors told him she'd died of pneumonia, but he thinks the trauma made her give up the will to live.
Captain Defenestrator